builtins test: Move clear_cache_test.c from a mprotect()ed global to a mmap()ed variable
builtins test: Move clear_cache_test.c from a mprotect()ed global to a mmap()ed variable

ld64 in the macOS 10.15 SDK gives __DATA a maxprot of 3, meaning it
can't be made executable at runtime by default.

Change clear_cache_test.c to use mmap()ed data that's mapped as writable
and executable from the beginning, instead of trying to mprotect()ing a
__DATA variable as executable. This fixes the test on macOS with the
10.15 SDK.

PR43407.

Differential Revision: https://reviews.llvm.org/D67929

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@372849 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt